Presently, traditional eyeglasses can be classified into nearsighted glasses for correcting the nearsightedness of nearsighted users, ornamental eyeglasses for making one fashionable, and sunglasses for blocking the strong sunlight. To increase wearing convenience, related manufacturers develop and design various attaching structures for attaching auxiliary eyeglasses having an additional function to main eyeglasses with a main function, in order to avoid additionally preparing another pair of eyeglasses having the additional function, such as the sunglasses. Attaching structures for auxiliary eyeglasses have various different designs. For example, a plurality of magnets are used as the attaching structure, wherein the magnets are provided on two extensions of a frame of main eyeglasses and two connecting arms of a frame of auxiliary eyeglasses for positioning the auxiliary eyeglasses on the main eyeglasses by the magnetically attractive force between the magnets. Alternatively, a plurality of screwing members are used as the attaching structure, wherein the screwing members are screwed through two extensions of a frame of main eyeglasses into two connecting arms of a frame of auxiliary eyeglasses for positioning the auxiliary eyeglasses on the main eyeglasses. Similarly, a pair of engaging hooks can be used as the attaching structure, wherein the engaging hooks are provided on a frame of main eyeglasses and a frame of auxiliary frame for positioning the auxiliary eyeglasses on the main eyeglasses by engaging with each other.
It is therefore tried by the inventor to develop a positioning structure for auxiliary eyeglasses to improve the conventional attaching structures between main eyeglasses and auxiliary eyeglasses as described above, so as to simplify the manufacture of the auxiliary eyeglasses, stably position the auxiliary eyeglasses on the main eyeglasses, and easily detach the auxiliary eyeglasses from the main eyeglasses.